Fix ambiguity in API if no matching system language is found

R=reed@google.com, wangxianzhu@chromium.org

Author: djsollen@google.com

Review URL: https://codereview.chromium.org/26325003

git-svn-id: http://skia.googlecode.com/svn/trunk/include@11641 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/ports/SkTypeface_android.h b/ports/SkTypeface_android.h
index 2166e08..0996740 100644
--- a/ports/SkTypeface_android.h
+++ b/ports/SkTypeface_android.h
@@ -36,7 +36,9 @@
  *
  *  @param uni  The unicode character to use for the lookup.
  *  @param lang The null terminated string representing the BCP 47 language
- *              identifier for the preferred language
+ *              identifier for the preferred language. If there is no unique
+ *              fallback chain for that language the system's default language
+ *              will be used.
  *  @param name The family name of the font file containing the unicode character
  *              in the preferred language
  *  @return     true if a font is found and false otherwise